October 2010

10/29/2010

Before creating a profile, we create a work plane for it. It makes a lot of sense to start working in the Top Plane when you are creating a box-like junction structure; then place a rectangular profile in that plane that defines the outer edges of the structure.

To make a work plane current so you can create geometry in it, you can right click on the work plane in Content Builder and hit Set View. Also, all the content creation tools for the work plane are located in the right click menu of the work plane. We will begin by creating a rectangular profile in the Top Plane.

The actual size of the square representing the work plane is 30x30. In situations like this, I prefer to attach the front and left edge of the rectangular profile to the lower left corner of the Top Plane. This way I can utilize the Front and Left Planes if needed without creating offset views. Again, this is my preference, but I find it helpful.

When drawing your geometry or creating your profile with the "quicky" commands, there are two schools of thought:

I prefer to draw to scale because I am happier that way. I think beginners should definitely draw to scale. If you are not used to the way the geometry responds when corresponding parameters values are changed, you may find a corner of your box lengthening to the right instead of the left (refer to Part Builder VI: Set Parameters). If drawing to scale, relative or absolute coordinate entry will be a helpful drawing aide.

In this example the rectangular profile will be 48x48 so we can OSNAP to the lower left corner of the work plane and specify the location of the opposite corner with relative coordinates.

After defining two opposite corners, a rectangular profile is created. In the Content Builder, notice that when the Top Plane is expanded, geometry consisting of four lines and four points is displayed. Also, coincident and perpendicular constraints are displayed. We will cover constraints in the next post.

Next you must get your mind out of the grade line because when we profile in Part Builder, we are creating a closed 2-dimensional shape around the outside of a feature which can be projected away from a plane to a certain distance and/or to a certain shape for the purpose of creating a 3-dimensional figure. Think of the profile of your face defining the 2-dimensional shape of your head; if we extrude away from this profile and transition to your ear we've created half the shape of your head. Sculpting, parametric style.

In an effort to break this information down into palatable chunks, some of these posts will be presented in two parts i.e. A and B parts. Part A will contain definitions and Part B will contain workflow. Here are your definitions for Profiles. We will talk about how these items are used in Part B.

Work Planes: Use work planes to model critical areas of your structure. Any area where a change in geometry occurs should have a work plane assigned to it. For example, a manhole with a conical riser could have a work plane at the top of the frame, one at the intersection of the frame and riser, and one that occurs where the riser meets the barrel of the structure.

Geometry: Within work planes, you would add geometry. Any type of geometry you would draw with an endpoint i.e. a line or arc will come in with its endpoints constrained to points. Think of this as a type of marriage between the points themselves and these endpoints. Geometry used to model parts must be of type AECCU_COL_GEOMETRY which simply means it must be drawn using the tools from the Add Geometry menu. If geometry from one work plane must be used in another work plane, there are commands that will reference that geometry.

Constraints: To set up physical relationships between geometry, constraints are applied. Constraints are used to maintain perpendicular, parallel, concentric, tangent relationships between geometry. Equal dimensional and symmetrical relationships can be set up as well. Coincident constraints ensure that points and endpoints of geometry stay with each other. Normal constraints are applied when the tangent of a curve must remain perpendicular to another curve or line. Midpoint constraints locate the midpoint between two entities. We will talk about applying constraints in Part Builder III. But is important that you understand them as you are creating your profile.

Profiles: When modeling in work planes, geometry is used to create closed areas called profiles. These profiles are then projected away from the work plan for the purpose of creating a 3-dimensional portion of the structure. We create custom profiles by selecting the individual geometry that forms these shapes. However, there are three "quicky" profile tools which define geometry, constraints, and the profile at the same time: circular, rectangular, and oval.

10/27/2010

The type of part we will focus on for the next series of posts will be a box-like junction structure, specifically a curb inlet.

Let's type “Partbuilder” at the command line.

Once the Catalog Screen opens up, hit the option for creating a new part.

Personally, I prefer to put my parts that are under construction in a “Test” chapter to avoid littering the functional folders. Also, I like to attach version numbers to the end of my part name so that I have a version of the part each time it was tested which makes it easier to go back in time if you need to redesign your approach. And also, this may be a no-brainer, but be sure you are working in a folder you can write to.

Once in the Part Builder environment, immediately go to the Content Builder palette and expand Part Configuration.

﻿Configure the Part Type as a Junction Structure.

Configure the Bounding Shape as a Box.

Hit the Save the Part button. This will bring in the model parameters needed to define your part.

The model parameters brought in are basic parameters which are to be configured in inches:

Instead of breathing life into my old blog Building the Perfect Template, I've decided to start new. I plan to kick this blog off by posting some of the content of my AU 2010 class which is intended to reveal the mysteries of Part Builder.

Modeling in Part Builder is not at all like modeling in AutoCAD Civil 3D. Although you have access to the same commands, you are not using arcs, lines, and circles to model a part. All commands are launched from the Content Builder which is the palette that appears on the left after launching Part Builder and then opening or creating a new part.

The workflow for building parts consists of the following phases:

Define

Profile

Constrain

Dimension

Apply Modifiers

Set Parameters

Validate

Test Part

Repeat 2 - 8 for additional part features

Therefore, there will be 9 posts to follow regarding Part Builder on each of the phases above.